This kit raises the hopper so you can stack two disks. It not only doubles the capacity of the disks but it makes very fine adjustments possible. Most powders can be adjusted up or down .1 grain with different combinations of disks. Complete listing of combinations, 4 extra disks, screws and risers are included. Size Adjusts Up Or Down .1 gr Type Double Disk Powder Measure Kit Color 1 Model Double Finish Black Series Disk Kit Caliber all Capacity Double Material Nylon Quantity 2 Disks/Screws